Pyongyang, September 4 (KCNA) -- Nuclear contamination is expanding due to the crippled nuclear power plant in Japan.

Radioactive cesium-137 and cesium-134 were respectively detected 150 000Bq and 130 000Bq per kg of the seabed soil off the Fukushima Nuclear Power Plant, according to the recent survey data.

This indicates that an immense amount of radioactive substances are settled in the seabed, the data said. If waves rise high by storm, radioactive substances will be carried to farther sea and accordingly radioactive level of sea water will radically rise.

Radioactive substance above the standard level was detected in fish caught in a swamp in Gunma Prefecture.